Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of
the registrant under any of the following provisions (see General Instruction A.2. below):

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this
chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or
revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 8.01.

Other Events

On June 5, 2018, Endurance International Group Holdings, Inc. (the
Company) announced the settlement of the previously disclosed investigations by the U.S. Securities and Exchange Commission (SEC) into the Company and its subsidiary Constant Contact, Inc. (Constant Contact). The
Company and Constant Contact agreed to settle with the SEC by consenting to the SECs entry of a cease and desist order (the Order), without admitting or denying the SECs findings set forth in the Order, and by paying a civil
monetary penalty in the amount of $8 million. The Order is available in the Administrative Proceedings section of the SECs website at https://www.sec.gov/litigation/admin.shtml.

The settlement does not require any changes to the Companys historic financial information. The Company accrued the $8 million penalty in its
fiscal quarter ended September 30, 2017 and will pay the penalty in the fiscal quarter ending June 30, 2018.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by
the undersigned hereunto duly authorized.